Definition of "barbarous"

The original Turkish tongue was somewhat barbarous, but extremely forcible and concise when spoken.

1880, Charles Wells, “Introduction to the second edition”, in James Redhouse, Redhouse's Turkish Dictionary, page vii

It is the remark of an ingenious writer, should a barbarous Indian, who had never seen a palace or a ship, view their separate and disjointed parts, and observe the pillars, doors, windows, cornices and turrets of the one, or the prow and stern, the ribs and masts, the ropes and shrouds, the sails and tackle of the other, he would be able to form but a very lame and dark idea of either of those excellent and useful inventions.

1801, Isaac Watts, The improvement of the mind, or A supplement to the art of logic

I felt vaguely he was a sneak, and remained quite unmollified by advances on his side, which, in a boy's barbarous fashion, unless it suited me to be magnanimous, I haughtily ignored.

1923, Walter de la Mare, Seaton's Aunt

Direct my weapon to his barbarous heart,That thus oppoſeth him againſt the Gods,And ſcornes the Powers that gouerne Perſea.

c. 1587–1588, [Christopher Marlowe], Tamburlaine the Great. […] The First Part […], 2nd edition, part 1, London: […] [R. Robinson for] Richard Iones, […], published 1592; reprinted as Tamburlaine the Great (A Scolar Press Facsimile), Menston, Yorkshire, London: Scolar Press, 1973, Act II, scene vi

I did but prompt the age to quit their cloggsBy the known rules of antient libertie,When strait a barbarous noise environs meOf Owles and Cuckoes, Asses, Apes and Doggs

1673, John Milton, I did but prompt the age to quit their cloggs